Polyhemoglobin-tyrosinase, an oxygen carrier with murine B16F10 melanoma suppression properties: a preliminary report

Melanoma now represents the fifth most common cancer in North America and it has increased dramatically in the past decade. One of the approaches shows that lowering of tyrosine level can inhibit the growth of melanoma in cell culture and in mice bearing B16BL6 melanoma. However, human cannot tolerate the tyrosine restricted diets for lowering tyrosine due to nausea, vomiting, and severe body weight loss. We therefore prepare a novel soluble polyhemoglobin-tyrosinase complex. Our studies show that this preparation can lower systemic tyrosine level in normal animals. This preparation also prevents the native tyrosinase from having adverse effects and from rapid removal after injection. In cell culture study, we find that this preparation inhibits the growth of murine B16F10 melanoma culture. Furthermore, in animal studies we observe that daily intravenous injection of this polyhemoglobin-tyrosinase preparation significantly delays the growth of B16F10 melanoma in mice, without causing adverse effects or changes in the growth of the treated animals.